Although metabolic imaging with the PET radiopharmaceutical 2-[18F]fluoro-2-deoxyglucose (FDG) has been successfully used for the evaluation of melanoma and sarcoma, there is interest within the nuclear medicine community in the development of novel PET tracers that would provide additional diagnostic information on these afflictions. Several investigational tracers that bind to specific target sites on tumors have been examined as biomarkers for PET studies of patients with melanoma and sarcoma. The translation of preclinical research tracers to human-use PET radiopharmaceuticals requires several developmental steps to be accomplished. Production of positron-emitting radionuclides from cyclotrons and generators is discussed, together with robust radiolabeling techniques that can be used for the incorporation of these nuclides into the molecular architecture of radiopharmaceuticals. Comprehensive quality control testing must be performed to assure safety and efficacy and thereby achieve regulatory approval for use of investigational radioactive drugs in human subjects. Several investigational PET studies of melanoma and sarcoma have been performed using positron-emitting amino acids, hormone receptor ligands, nucleotides, hypoxia radiosensitizers, and tumor receptor-targeting peptides. Differences between these findings and those of FDG-PET encourage further development of new radiopharmaceuticals for PET imaging of unique tumor targets. Such novel radiopharmaceuticals may be synergistic with traditional FDG metabolic imaging, improve our understanding of tumor pathophysiology, and facilitate personalized care of patients with melanoma or sarcoma.
- Quality control
- Translational research